Electromagnetic carbon-pile regulators



Feb. 3, 1959 STAMBERGER 2,872,554

ELECTROMAGNETIC CARBON-FILE REGULATORS Filed Oct. 22, 1956 2 Sheets-Sheet 1 Feb. 3, 1959 A. STAMBERGER 2,872,554

ELECTROMAGNETIC CARBON-FILE REGULATORS Filed Oct. 22, 1956 2 Sheets-Sheet 2 ELECTROMAGNETIC 'CARBON-PILE REGULATORS Andrew Stamberger, Brockley, London, England, assignor to J. Stone & Company (Deptford) Limited, Deptford, London, England. 7.

Application October 22, 1956, Serial No. 617,557

Claims priority, application Great Britain 7 I October 22, 1955 Claims. (Cl. 20151) This invention concerns improvements relating to electro-magnetic carbon-pile regulators provided with dashpots. With forms of dashpot heretofore employed, in a regulator whose armature has to travel a comparatively long distance from the off stop position before the pile resistance increases well above its minimum value, sluggishness of the dashpot may involve danger of an overvoltage being produced before the regulator cuts in or while it is cutting in. Other conditions may also tend to lead to overvoltage.

According to the present invention, an electro-magnetic carbon-pile regulator has a dashpot which is provided not only with a fixed aperture vent, but also with means for automatically relieving pressure inside the dashpot during operation of the regulator in one direction, for example during cutting in of the regulator.

The pressure-relief means may consist simply of a ball valve controlling communication between the inside of the dashpot and a further vent, the ball being loaded towards its seat by a spring. Alternatively, it may consist of an auxiliary flexible diaphragm which is shaped so that it will billow out upon operation of the regulator in the said one direction.

Two embodiments of the invention by way of example will now be more fully described with reference to the accompanying drawing, in which:

Figure 1 is an elevation of a dashpot,

Figure 2 a diametrical section therethrough,

Figure 3 an axial section to a larger scale through pressure-relief means for the said dashpot,

Figure 4 is a diagrammatic side elevation of a regulator embodying such a dashpot, and

Figure 5 a section through pressure-relief means of an alternative kind.

In the embodiment of the invention illustrated in Figures 1-4, the dashpot comprises a flexible diaphragm 1 whose inner area is clamped between discs 2, 3 and whose outer periphery is clamped by a ring 4 to a dished plate 5. The plate 5 is formed with a channel 6 (Figure 2) opposite the free annular portion 7 of the diaphragm 1. For mounting the dashpot on a fixed supporting structure, it is provided with pillars 8 riveted into the discs 2, 3. The part upon which the dashpot is to act is connected to eyelets 9 formed on the ring 4 and plate 5. The use of such a dashpot in conjunction with a carbon pile regulator is illustrated and described in the specification of application Serial No. 399,794, now Patent No. 2,828,395, and the arrangement there adopted is shown purely diagrammatically in Figure 4 of the present specification. The dashpot is mounted on the fixed supporting structure 25 of the regulator by the pillars 8 and the plate 5 is connected to the rockable clapper 26 of the regulator by links 27 extending from the eyelets 9. The clapper 26 carries the armature 28 coacting with the magnet core 29, acts upon the carbon-pile 30 through a strut 31 and is itself acted upon by a main control spring 32. The oft stop is indicated at 33.

nited tates Patent O "ice The pressure-relief means of the dashpot consists simply of a ball-valve device mounted at the middle of the plate 5. The valve body 10, which is riveted (Figure 3) into a hole in the plate 5, has a bore 11 leading from the interior of the dashpot to a seating 12for the ball 13. Beyond the said seating, the body is formed with a cavity 14 having vents 15 and housing a helical, slightly conical, compression spring 16 loading the ball 13 towards its seating 12. The spring abuts against a cap 17 sprung onto the end of the body 10. A fine bore 18 in a spigot 19'fixed in the body 10 forms a permanently open fixedaperture vent from the bore 11.

During normal operation of the regulator, in which the movement of the plate 5 is relatively small, the ball 13 will be held against its seating 12 by the spring 16 and the interior of the dashpot will be vented solely by way of the fine bore 18, so that the dashpot will exert a gentle damping effect upon the clapper 26 and armature 28. At a certain pressure produced inside the dashpot by an abnormal movement of the armature, for example due to the aforesaid initial large movement of the clapper 26 away from the stop 33 when the regulator cuts in, the ball 13 will be forced off its seating 12 to open communication between the inside of the dashpot and the vents 15 and will thus automatically relieve the pressure.

The size of the vents 15 will depend upon the damping desired after the ball has been forced off its seating. For some purposes, the additional venting effect may be of the same order as that provided by the fine bore 18.

After the regulator has cut in, the valve recloses and may remain inoperative during normal regulating movements of the armature. However, the valve may be de' signed so that it can open slightly even during normal operation of the regulator, thereby improving the speed of its response in the direction for increasing pile resistance.

The ball 13 is made of a light-weight material, for instance from ground glass, in order to minimize the disturbing effects upon it of accelerations of, say, an aircraft in which the regulator is mounted. The cavity 14 is made substantially larger than the ball in order to reduce the danger of sticking. The spring 16 is designed with such a low rate that the force with which it loads the ball 13 will be sufiiciently constant without the necessity for adjustment means. However, a screw abutment may be provided in place of the cap 17, if desired.

The dashpot illustrated is designed to contain a very small volume of air when in the non-distended condition. The riveting for the pillars 8 and valve body 10 should therefore project as little as possible into the interior of the dashpot.

In the alternative arrangement illustrated in Figure 5, a shallow dish or cup member 20 is mounted with its concavity outwards on a wall of the dashpot, for example the plate 5, the wall and the member 20 being pierced by a central opening 21. Normally this opening 21 is sealed by a small auxiliary rubber diaphragm 22 whose edge is held in air-tight fashion to the edge of the said member by being bonded or otherwise joined thereto or clamping, the diaphragm 22 being preferably shaped to assume the internal concave form of the dish or cup. When pressure tends to develop inside the dashpot, however, the diaphragm 22 will billow outwardly away from the member 26, as indicated by a broken line, and will afford pressure relief to the dashpot by virtue of the increase in volume. This arrangement has the advantage that the moving part is relatively light and will be little affected by acceleration. Consequently, it can be designed to act at a lower pressure than is possible with the spring-loaded ball valvev I claim:

1. An electromagnetic. carbon-pileregulator comprising a dashpot provided with a fixed-aperture vent, and further pressure-relief means for automatically relieving pressure inside the dashpot during operation ofvther regulator in one direction.

2. Aregulator as claimedin claim 1, wherein the further pressure-relief means comprises a valve body having a further vent,. a spring-loaded ball valve controlling communication between the'interior of said dashpot and said further vent;v

3. A regulator as claimed in claim 2, wherein the spring isv a helical, slightly conical,v compression spring.

4. A regulator as claimed in claim 2, wherein saidv'alve body is provided with a cavity, said ball? being made of a light material and being accommodated freely in said cavity, in the'valve body, said springalso being accom References Cited in the file of this patent UNITED STATES PATENTS 2,443,252 Kelly June 15, 1948 2,489,071 Austin Nov. 22, 1949 FOREIGN PATENTS 163,521 Australia Ian. 7, 1954 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 2 872554- February 3 1959 Andrew Stamberger It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

In the heading to the printed specification, line 9, for "October 22 1955" read October 26, 1955 Signed and sealed this 21st day of November 1961.,

(SEAL) Attest:

ERNEST W. SWIDER DAVID L. LADD Attesting Officer Commissioner of Patents USCOMM-DC UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 2 ,872,554 February 3 1959 Andrew-Stamberger It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below In the heading to the printed specification line 9 for "October 22 1955" read October 26, 1955 Signed and sealed this 21st day of November 1961,

(SEAL) Attest: v

ERNEST W. SWIDER DAVID L. LADD Attesting Officer Commissioner of Patents USCOMM-DC 

